<div class="item1">no margin</div>
<div class="item2">-20px top margin</div>
.item1,
.item2 {
  height: 100px;
  text-align: center;
  line-height: 100px;
}

.item1 {
  background-color: #aabbcc80;
}

.item2 {
  background-color: #11bbdd70;
  margin-top: -20px;
}

External CSS

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External JavaScript

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